Interactive Effects of Drip Irrigation and Nitrogen Fertilization on Wheat and Maize Yield: A Meta-analysis

Population growth and climate change are pushing the need for sustainable food production and reduced water usage in agriculture due to limited water resources. Irrigation and fertilization have been proposed to improve crop water and nutrient utilization and potentially sustain or boost yields with less water, but its effect on crop yield can vary widely. This study conducted a meta-analysis to examine the effects of climate, soil conditions, and agricultural practices on maize and wheat yields in field conditions, especially when irrigation and nitrogen fertilization are used. The researchers used systematic literature searches to gather data on grain yields for maize and wheat from peer-reviewed publications available on Web of Science and Google Scholar. In summary, the meta-analysis of 24 peer-reviewed studies, which included a total of more than 706 observations, revealed that the application of irrigation and fertilization resulted in a respective yield increase of 9.20% for maize and 17.32% for wheat grain. Average maize grain yield was 9539.15 kg ha-1 in the irrigation and fertilization treatment and 8661.57 kg ha-1 in the control. Similarly, average wheat grain yield was 7011.58 kg ha-1 in the irrigation and fertilization treatment and 5797.24 kg ha-1 in the control. The assessment of effect size heterogeneity showed that the study effect sizes were significantly heterogeneous. This research proposes that by combining effective field management methods with nitrogen fertilizer and irrigation, sustainable and climate-resilient agricultural production can be achieved while mitigating soil and environmental damage.